Device for air-intermingling multifilament yarns

Abstract

The device comprises a body (1, 2) with a continuous yarn channel into which terminate a blast nozzle (7) and a threading slot (8). The yarn channel is defined by two hollow wall surfaces (11.1, 11.2 and 12.1, 12.3) emanating from respectively one rim of the orifice of the threading slot (8) and being symmetrical with respect to a plane of symmetry (E) containing the axis (A) of the yarn channel. The two wall surfaces contain jointly at least four component surfaces (11.1, 11.2, 11.3, 12.1, 12.2, 12.3) of which at least two (11.1, 11.2, 12.1, 12.2, 12.3) are planar. The rim of the orifice of the threading slot (8) lying on the side of the blast nozzle (7) has a larger spacing from the plane of symmetry (E) than the other rim. Thread guides (13) are inserted in the body (1, 2) at both ends of the yarn channel, keeping the multifilament yarn to be air-bulked at a distance from the orifice of the blast nozzle (7). This geometry achieves, with a low consumption of blowing air, high air-bulking densities, measured as the number of air-bulk knots per meter of yarn length.

I claim: 
     
       1. A device for intermingling multifilament yarns, comprising: a body (1, 2) composed of two sections secured to one another, namely a nozzle unit section (1) and an impingement unit section (2), said nozzle unit section (1) being formed with a first continuous linear groove defined by a first hollow wall surface (11), and with at least one blast nozzle (7) having an orifice in said first hollow wall surface (11),   said impingement unit section (2) being formed with a second continuous linear groove defined by a second hollow wall surface (12) which lies in opposition to said orifice,   said first and second hollow wall surfaces (11, 12) together defining a continuous yarn channel (6) having a longitudinal axis (A), and said hollow wall surfaces (11, 12) each being symmetrical with respect to a plane of symmetry (E) containing said longitudinal axis (A),   a continuous threading slot (9) communicating with said yarn channel provided between said nozzle unit section (1) and said impingement unit section (2) and extending to a rim of said first hollow wall surface (11) and to a rim of said second hollow wall surface (12),   said rim of said first hollow wall surface (11) having a greater spacing from said plane of symmetry (E) than said rim of said second hollow wall surface (12),   said first and second hollow wall surfaces (11, 12) defining said yarn channel (6) together being composed of at least four component surfaces of which at least two are planar,   and thread guide members (13, 14) fixed directly in said nozzle unit section (1) at both ends of said yarn channel (6) for keeping any multifilament yarn, which is tensioned over said thread guide members (13, 14), at a distance h from said first hollow wall surface (11).   
     
     
       2. Device according to claim 1, wherein said at least one blast nozzle (7) is symmetrical with respect to the plane of symmetry (E). 
     
     
       3. Device according to claim 1, wherein the first and second hollow wall surfaces (11, 12) have a spacing H between them as measured in the plane of symmetry (E), and wherein the thread guide members (13, 14) are positioned so that said distance h of a multifilament yarn from the first hollow wall surface (11), as measured in the plane of symmetry (E), amounts to 5-50% of the spacing H. 
     
     
       4. Device according to claim 1, wherein lateral openings (15, 16; 17, 18) emanate from the yarn channel (6) in front of the thread guide members (13, 14) as seen from the orifice of the blast nozzle (7). 
     
     
       5. Device according to claim 4, wherein the cross section of the outlet openings (15, 16; 17, 18) is larger than the portion of the cross section of the yarn channel (6) blocked by the thread guide members (13, 14). 
     
     
       6. Device according to claim 1, further including means for guiding at least one multifilament yarn (M) toward one of the thread guide members (13, 14) and means for taking off the yarn from the other thread guide member in direction which lie approximately in the plane of symmetry (E) and form an angle (α) of 2°-20° with the longitudinal axis (A) of the yarn channel (6).